Bottom Line:
Based on these results Cyphacolus syn. n. is placed as a junior synonym of Odontacolus which is here redefined.Odontacolus markadicus, previously only known from India, is here recorded from Brunei, Malaysia, Sri Lanka, Thailand and Vietnam.The relationships, distribution and biology of Odontacolus are discussed, and a key is provided to identify all species.

Mentions:
Terms. Morphological terminology follows Masner (1980) and Mikó et al. (2007) except for the term “lagrimal” (abbreviated as ‘lag’ in figures and derived from the Spanish word “lagrimal”) that is presented here and defined as a subtriangular area between the malar sulcus and the compound eye. Normally the malar sulcus expands in a ‘V’ shape towards the compound eye in this area. The structure was first observed in Odontacolus gentingensis sp. n. (Fig. 36). Abbreviations used in text: antennomeres (A1, A2, etc); anterior sterna carina (ASC); furrow (Frw); metasomal tergites (T1, T2, etc); metasomal sternites (S1, S2, etc); occipital carina (occ).

Bottom Line:
Based on these results Cyphacolus syn. n. is placed as a junior synonym of Odontacolus which is here redefined.Odontacolus markadicus, previously only known from India, is here recorded from Brunei, Malaysia, Sri Lanka, Thailand and Vietnam.The relationships, distribution and biology of Odontacolus are discussed, and a key is provided to identify all species.